At ranch ; in between water mill and little pond
Sprite island ; check the farming fence
Lighthouse island (go by boat at your ranch); the back wall of the lighthouse
Vendure island ; bush between Chen and Marivelles shops
Sprout island ; 2 sunstones here; if unlocked Will, the barrel at the front on his yacht; the well next to Gannon's shop as well
Mystic islands ; bell in front of church; left-side lamp post in front of witches house
Mushroom island ; base of largest right-side mushroom
Volcano island ; lava flow next to island's sign
Animal island ; check the pond
Link island ; on the bridge leading to island( check the left post)
Rice island ; northeast corner, check the tree furthest to the right
Tree island ; bush in southeast corner
Greenhouse island ; bush on left edge of island
Give gifts to ALL characters ( even ones with no significance) and they will give you sunstones. If you keep on raising their friendship after you give them gifts to 2 hearts, then enter their house and the master of the house ( for example Taro if you enter his home of Maribelle) will give you a sunstone. Note: you need to have all members of the house at 2 hearts before you can get a sunstone from the house master.
Harvest Goddess ; do the same like all other characters and raise her hearts to 2 then enter island and she'll be in front of boat and give you a sunstone.
Added by: dragongirl101 Jan 14th 2013, ID#17797